Electro-mechanical interlock



Dec. 20, 1966 Filed Deo. '7, 1964 H. R. CRISPEN ET AL ELECTRO-MECHANICALINTERLOCK 2 Sheets-Sheet 2 arent Patented Dec. 2G, 1968 3,292,737ELECTRO-MECHANICAL INTERLCK Hibherd R. Crispen and Charles N. Fendrich,Harrisburg, Pa., assignors to Inclnator Company of America,

Harrisburg, Pa., a company of Pennsylvania Filed Dec. 7, 1964, Ser. No.416,334 12 Claims. (Cl. IS7-31) The present invention relates to yanelectro-mechanical interlock mechanism. More specifically, the presentinvention relates to an electro-mechanical interlock `mechanism forhoistway doors of elevators. Y

In elevator installations, it is customary to prevent the operation ofthe elevator car unless the hoistway doors at all floors are closed.Thus, the elevator car cannot be moved away from a given door until thehoistway door at that iloor is closed. This is generally accomplished byan interlock mechanism in which an electrical switch is held in an openposition to prevent completion of the operating circuit of the elevatorcar until the hoistway door is completely closed and mechanicallylocked. However, because ofthe inordinate expense `and impracticality ofoperating both the door lock and the elevator switch at exactly the sameinstant, there is always the possibility that a door will be left open ashort distance by accident and the elevator car will still operate withthis dangerous condition in existence.

It is therefore an object of the present invention to provide animproved interlock mechanism for doors in which opening of the door ashort distance will interrupt the circuit operating another mechanism.

A further object of the present invention is to provide an improvedinterlock mechanism for elevator doors in which opening of the door ashort distance will interrupt the circuit operating the elevator car.

Another object of the present invention is to provide an interlockmechanism for elevator doors in which opening the door a small amountwill interrupt the circuit operating the elevator car but the door willbe prevented from opening more than a predetermined distance from thejamb.

A further object of the present invention is to provide an improvedinterlock mechanism for elevator doors in which a door left part-wayopen wil-l interrupt the circuit operating the elevator car while open,but a return mechanism will completely close the door therebyrecompleting the circuit.

till another object of the present invention is to provide an improvedinterlock mechanism for elevator doors in 'which the circuit operatingthe elevator car is interrupted if the latch mechanism of the hoistwaydoor is not locked internav ly.

In accordance with the present invention, the above objectives areaccomplished by providing a three-position latch mechanism for ahoistway door. In a rst position, representing the completely closedposition of the door, the circuit operating the elevator car is closedand the hoistway door is held in its completely closed position by aspring mechanism. In the second position, the door is a predetermineddistance from lthe jarnb, but is mechanically blocked from opening anyfurther, the circuit operating the elevator car is open and the latchmechanism is under spring tension tending pul-l the door completelyclosed. In its third position, the door is open, the circuit operatingthe elevator car is open and the latch mechanism has passed through acenter position and is held in its completely open position.

The above objects and advantages of the present invention will beapparent from the following detailed description, when read inconjunction with the drawings, wherein:

FIGURE l is a plan View, partially in section, of the interlockmechanism;

FIGURE 2 is a side elevational view, partially in section, of theinterlock mechanism;

FIGURES 3a, b and c, partially in section, show the three basicpositions of the latch mechanism; and

FIGURES 4a, b and c show the three basic positions of the electricalswitching circuit.

In the drawings, the numeral 10 designates a base plate verticallyvmounted on the door jamb 12, of an elevator hoistway opening. Mountedon the hoistway door 14 is lock bar 16. Lock bar 16 has formed therein,adjacent its upper edge land on its free end, a rectangular slot 18.Mounted near the lower end of plate 10 is terminal block 2! havingterminals 22, 24 and 26 mounted thereon. Also `mounted on plate It)above terminal block 20 is snap action switch 28, having contact button30 spring biased in its extended position. Attached to plate 10 throughswitch 23 is mounting plate 32. Attached to the rearward side of plate32 is snap action switch 34. Switch 34 has contact button 36 normallybiased in its extended position. Also pivotally attached to switch 34 onpivot 38 is operating arm 4i), which is adapted to press against andoperate contact button 36. Mounted on the free end of operating arm 44?is roller 42. Roller element 42 is adapted to cooperate with and act asa follower for generally circular com member 44. Clam member 44 ispivotally mounted on plate lti through pivot element 46. It is to benoted that when roller element 42 is riding -on the circular portion 48of cam member 44, contact button 36 is depressed, while, when rollerelement 42 is adjacent straight section 50 of cam member 44, contactbutton 36 is released and in its extended position. Mounted adjacent theperipheral edge of c-am member 44 and protruding therefrom arecylindrical lock pins 52 and 54, respectively. Lock pin 52 fits withinslot 18 when cam 44 is in the rst and second positions shown in FIGURES3a and 3b, but is free of slot 13 when cam member 44 is in the positionshown in FIG- URE 3c. Attached to the free end of lock pin 54 is one endof helical spring 56. The other end ot spring 56 is attached to mountingblock 58, which, in turn, is attached to plate 10. It is to be notedthat spring 56 is under tension and holds cam member 44 in the positionshown in FIGURE 3a when the door is completely closed. When the door isopened a predetermined distance, latch pin 54 moves to a point justshort of the center position, as shown in FIGURE 3b, in which positionspring 56 is further stretched and therefore tends to return cam 44 tothe position shown in FIGURE 3a. However, if cam member 44 is turn-edstill further to cause pin 54 to pass through the center position,spring 56 will tend to continue to rotate cam 44 to the position shownin FIGURE 3c and hold it in that position. Stop 60 on the peripheraledge of cam 44 limits the movement of cam 44 in a clockwise direction,while stop 62 limits the movement of cam 44 in a counterclockwisedirection. Accordingly, cam 44 moves through a preselected arc, from oneextreme position, counterclockwise through a center position and thenceto a second extreme position. In accordance with the present invention,this movement is contined to an arc representing approximately Alsoformed in the upper portion of the peripheral edge of cam 44 to arcuateslot 64. Slot 64 cooperates with movable cylindrical pin 66. Whencylindrical pin 66 is in its lowermost position and cam 44 is in theposition shown in FIGURE 3a, pin 66 abuts shoulder 63 of slot 64 andwhen cam 44 has passed through an arc sufficient to have pin 54 justshort of its center position, pin 66 abuts shoulder 70 of slot 64. Thus,it is clear that, when pin 66 is in its lowermost position, pin 66permits a limited arcuate movement of cam 44 to a position whereby pin54 is just short of its center position and cam 44 is being urged backto its original position of FIGURE 3a by spring 56. Also ymounted onblock 58 is snap -action switch 72. Switch 72 has contact button 74,normally biased in its extended position, which is operated by operatingarm 76 pivotally connected to switch 72 through pivot 78. Operating arm76 is in contact with collar 80 mounted in a xed position on pin 66.When pin 66 is in its lowermost position, operating arm 76 depressescontact button 74, and when pin 66 is raised, contact button 74 isreleased to its extended position. Connected to the upper end -of pin66, by means of manual pin lifting element 82, is solenoid core 84.Solenoid core S4 is surrounded by coil 86 which, when energized, isadapted to draw core S4 upwardly a distance sufficient for pin 66 toclear the outer periphery of cam 44 and to remove the pressure of collar80 from -operating arm 76, thereby releasing the contact button 74. Coil86 and core 84 make up a 24-volt solenoid S3 which is mounted on plate16 adjacent its upper end.

To facilitate the description of the operation of the'VY interlockmechanism of the present invention, FIGURES 3a, b and c have beenincluded to show the three basic positions of the latch mechanism.FIGURES 4a, b and c have also been included to show the positions of theswitches of the electrical system, when the latch mechanism is in theposition shown in `drawings 3a, i7 and c, respectively. Accordingly, inthe following detailed description of the operation of theelectro-mechanical interlock mechanism of the present invention,drawings 3a, 3b, 3c, 4a, 4b and 4c will be referred to in conjunctionwith FIGURES l and 2.

Referring rst to FIGURES 3a and 4a, it is to be observed that FIGURE 3ashows the latch mechanism in exactly the same position as it is shown inFIGURE l. The door in FIGURE 3a is completely closed. It is to beobserve-d that, with the latch mechanism in the position shown, spring56 wil-l hold cam 44 in the furthermost clockwise position permitted bystop 60. Ths position of cam 44 causes the pin 52 to press against thebottom and left side of slot 18 of lock bar 16, thereby holding door 14in its closed position. Pin 66 is in its lowermost position riding inarcuate slot 64, since, as will be pointed out hereinafter, solenoid 88is not energized. Finally, roller 42, attached to switch 34 throughoperating arm 40, is in contact with the peripheral edge 48 of cam 44.As shown in FIGURE 4a, switch 34 is norm-ally biased in its openposition, and when roller 42 is riding the peripheral edge 48 of cam 44the button 36 of switch 34 is depressed, thereby holding switch 34 inits closed position. When pin 66 is in its lowermost position, button 74Iof switch 72 is depressed by collar 80 through operating larm 76.Switch 72 is normally biased in its open position and therefore thedepression of button 74 closes switch 72. With door 14 completelyclosed, button 30 of switch 28 will be depressed. Switch 28 is normallybiased against contacts 90 and, therefore, when button 30 is depressed,switch 28 will be depressed against contracts 92, thereby bridging thesecontacts. Electrica-l line 94 is a live lead from a 24-volt sou-rce ofelectrical current and, as shown, is connected to terminal 22 of theelectro-mechanical interlock system, of each floor served by theelevator, through electrical line 96. Mounted in line 96 is rail switch9S, which is normally biased in its open position. For simplicity ofillustration, switch 98 is shown as a snap action switch but it may takeother forms. Rail switch 98 is tripped and closed when the elevator carreaches the oor in question. Electrical line 100 also originates at thesource of energy but comes from the right hand terminal, for example,terminal 26 of FIGURE 4a, of the previous interlock mechanism if thereis such an interlock interposed between the source of energy and theinterlock mechanism shown. In like fashion, electrical line 102, fromterminal 26 of the interlock mechanism shown, passes to a tenminal, suchas, terminal 24 of the next succeeding interlock mechanism or to afloating cord if no succeeding interlock mechanism exists. In any event,24 volts of electrical energy are impressed across lines 94 and 100. Byobserving FIGURE 4a, with the switches 34, 72 and 28 in the positionsshown, it is to be seen that, when the door is completely closed, coil86 is de-energized due to the fact that switch 28 is bridging contacts92 and contacts 90 are open. However, electrical energy is beingsupplied to the next succeeding interlock mechanism through line 94 andline 100 through contact 22, switch 28, switch 72, contact 26 andelectrical line 102. It should also be noted that this conditionpersists so long as the door is closed, irrespective of whether theelevator is at the iloor in question and rail switch 98 is closed orrail switch 98 is open as shown.

The next basic position of the latch system is shown in FIGURE 3b. InFIGURE 3b door 14 has been opened just far enough (about 1A of an inch)to release button 30 -of switch 28. Pin 66 has passed along arcuate slot64 until it is just about to touch shoulder 70 of slot 64. Roller 42 isstill riding on circular periphery 48'of cam 44 and is just about toleave this circular surface to ride along straight surface 50 on theperiphery of cam 44. In the position shown, pin 66 abutting againstshoulder 70 prevents cam 44 from turning any further. Also, since pin 66still rides in slot 64, collar y80 will still hold switch 72 closed. Pin52 is still in slot l1S of lock bar 16. Thus, the door cannot be openedany further because of the blocking action of pin 66 and pin 52. Inaddition, the door 14, when in this position, must be held open by theperson attempting to open the door, due to the fact that spring 56 isextended further than it was in FIGURE 3a and cam 44 is being urged in aclockwise direction, thereby pulling lock bar 16 inwardly through pin 52and door 14 to the closed position. Referring now to FIGURE 4b, theelectrical switch system is in the condition recited below. First ofall, since roller 42 is still on -circula-r periphery 48 of cam 44,switch 34 is still depressed thereby maintaining switch 34 in its closedposition. However, the opening of the door and the release of button 30has caused switch 28 to be released and bridge contacts 90. If we nowassume that the elevator car has not reached the floor in question andswitch 98 is still open, the circuit through coil S6 is still not madeand pin 66 remains in its lowermost position; but, except for the factthat rail switch 9S is still held open, the circuit would be completethrough coil 86. Switch 72 is also still depressed and therefore closed,since pin 66 is still in its lowermost position, but no current can flowin control circiut 102 to the next succeeding interlock because contacts92 of switch 28 'are open. Stated differently, the circuit through coil86 will remain open so long as the door is closed or the elevator car isnot at the floor in question, and, so long as the elevator car is not atthe floor in question the door cannot be opened further and, in fact,spring 56 will pull it completely shut.

Now assume that the elevator car is at the oor in question and switch 98is closed, as shown in FIGURE 4b. The circuit through coil 86 is nowcomplete and Coil 86 is energized pulling core. 84 into coil 86 and, bythe same action; lifting -pin 66 out of slot 64. The lifting of pin 66frees cam 44- to rotate further in a counterclockwise direction. By thesame token, lock bar I6 is free to move outwardly away from theinterlock mechanism and the door 14 is free to open. Opening door 14 aslight bit further will rotate cam 44 counterclockwise and cause roller42 to leave circular periphery 48 of cam 44 and enter upon straightsurface 5t) of the periphery of cam 44.

FIGURE 3c shows the latch mechanism with the door 14 open still `furtheror, in essence, in its completely open position. In this completely openposition a number of changes take place. As previously indicated, roller42 is now riding surface 50 of cam 44, rather than surface 48. Inaddition, pin 66 has been lifted from slot 64 and is riding circularperiphery 4S of cam 44. Pin 54 has passed to the right of the centerline through the point of pivot of cam 44 and the spring 56 will thencontinue to pull cam 44 in a counterclockwise direction until stop 62strikes mounting block S8 and stops this rotation. Finally, pin 52 has`moved out of slot 18 of lock bar 16, thereby completely releasing lockbar 16 and door 14. The door may then be opened completely and will notbe reclosed by the latch mechanism. As shown in FIGURE 4c, when the dooris completely open, roller 42 is riding straight surface 50 of cam 44and has therefore permitted operating arm 40 to move upwardly and to theright and release button 36 of switch 34. Since switch 34 is normallybiased in its open position, the biasing spring will open switch 34 asshown. Since pin 66 has been raised, this pin, in turn, has raisedcollar 80 and permitted operating arm 76 to raise and release button 74of switch '72. Since switch 72 is normally biased in its open position,the release of button 74 will open switch '72.. Since the door is open,it is not pressing against vbutton 30 of switch 28 and, therefore. thisbutton is released. Since switch 28 is normally biased against contacts90, the release of button 30 will cause switch 28 to remain in theposition where it bridges contacts 90. Also, since the elevator is atthe floor in question, switch 9S, which is normally biased in an openposition, will be held closed by the elevator car. Thus both the circuitthrough the coil of the interlock on the floor in question is openbecause of open switch 34 and the circuit to the next succeedinginterlock mechanism is open, since switch 72 is also in its openposition, and switch 28 has also opened contacts 92. This conditionpersists so long as the door is open. Further, accidental pushing ofbutt-on 30, thereby closing contacts 92, will not alter the situation.

FIGURES 3c and 4c also show the condition just prior to closing door 14and reversing the previously described sequence of steps. Specically,when door 14 is closed, lock bar 16 contacts pin 54, as shown in FIGURE3c, and further closing will cause lock bar 16 to push against pin 54and rotate cam 44 in a clockwise direction overcoming the tension ofspring S6. The rotation of cam 44 in a clockwise direction causes pin 54to pass the center line through pivot of cam 44. At the same time, pin52 again begins to enter slot 18 of lock bar 16. When pin 54 passes thecenter line of cam 44, the spring 56 again takes over and urges cam 44in a clockwise direction as far as possible, that is, until stop 60contacts mounting block 5S. This continued clockwise rotation of cam 44causes pin 52, which is now in slot 83, to pull lock `bar 16 and door 14to the completely closed position, as previously shown and described inFIGURES 3a and 4a. The switches 34, 72 and 2S will return to thepositions shown in FIGURE 4a and when the elevator car leaves the oor inquestion, switch 9S will open.

It is to be understood that the present invention may be utilized withequal facility on a door which is hinged from the side of an opening, aswas assumed in the present description, `or on a sliding door; and,while an interlock for a left hand door is shown, right hand models canobviously be made. In addition, other variations and modifications willbe obvious to one skilled in the art. For example, the circuit supplyingenergy to the elevator car can be made to include contacts 92 of switch28 so that the car will not move `when a hoistway door is open, as inFIGURES 3c and 4c, or is ajar, as in FIGURES 3b and 4b; `or it caninclude switch 72 so that the car will not move when the door has beenopened beyond the point illustrated by FIGURE 3b. Therefore, the presentinvention is to be limited only in accordance with the appended claims.

We claim:

1. An electro-mechanical interlock mechanism for elevator hoistway doorscomprising:

(a) a generally rectangular base plate attached to the door jamb of thehoistway opening in a vertical manner;

(b) a generally disc-shapcd cam member rotatably mounted on said baseplate near the center thereof;

(c) support block means rigidly attached to said base plate above saidcam and in the immediate vicinity thereof;

(d) two stops radially protruding from the edge of said cam and adaptedto cooperatively engage said block, a first of said stops engaging saidblock at a rst rotational position of said cam and the second of saidstops engaging said block at a second rotational position of said camabout of rotation from said rst position;

(e) a rst cylindrical pin means mounted on said cam and having its axisperpendicular to the face of said cam and its circumferential edgecoinciding with the circumferential edge of said cam and positioned onsaid cam such that it will be on `one side of a vertical plane passingthrough the axis of rotation of said cam when said cam is in its saidfirst rotational position and on the other side of said plane when saidcam is in its second rotational position;

(f) second cylindrical pin means mounted on said cam and having its axisperpendicular to the face of said cam and its circumferential edgecoinciding with lthe circumferential edge of said cam and positioned onsaid cam such that its axis coincides with said vertical plane when saidcam is in its rotational position and more than about 30 of rotationfrom said vertical plane and on the same side of said vertical plane assaid first pin, when said cam is in its second position of rotation;

(g) helical spring means havin-g one end attached to said rst pin andits other end connected to said block on the side of said vertical planeto which said first pin rotates when said cam is in its secondrotational position;

(h) said cam having a sector-shaped slot formed in its edge beginning ata point adjacent said tirst stop and extending slightly more than about30 of rotation toward said second stop;

(i) third pin means having its central axis in alignment with saidvertical plane and slideably passing through said block for limitedvertical movement into contact with the upper edge of said cam in amanner such that said third pin will limit the rotation of said cam toabout 30 of rotation, when it is in its downward position and in saidsector-shaped slot, and will Contact the outermost peripheral edge ofsaid cam when it is in its uppermost position and said cam isapproaching said second rotational position;

(j) a solenoid mounted on said base plate adjacent its upper end andhaving a movable cylindrical core whose central axis is in alignmentwith the axis of said third pin;

(k) manually operable lift means holding said core and said third pinrigidly together and adapted to move said third -pin between itslowermost and its uppermost position;

(l) rst switch means, normally biased in its open position, mounted onsaid support block;

(m) collar means rigidly mounted about said third pin means above saidsupport block;

(n) arm means pivotally mounted on said first switch and having its freeend in Contact with the lower edge of said collar, said arm being heldoutwardly by the biasing force of said switch when said third pin is inits most uppermost position and being forced inwardly to overcome thebiasing force of said switch and close said switch when said third pinis in its lowermost position;

(o) said cam also having a flat chord formed -on its edge between saidrst stop and said first pin;

(p) second switch means, normally biased in its open position, mountedbelow said cam;

(q) follower means pivotally mounted on said second switch and havingits free end in Contact with the edge of said cam, said follower beingheld outwardly by the biasing force of said switch when said cam is inits second position of rotation and said follower is in contact with thestraight chord section of said cam and being forced inwardly to overcomethe biasing force of said switch and close said switch when said cam isin its second rotational position and said follower is in contact withthe circular section of said cam;

(r) third switch means mounted on said base -plate below said cam andnormally biased toward a rst set iof contacts to close said firstcontacts and normally biased away from a second set of contacts to holdsaid second contacts yopen until said biasing `force is overcome;

(s) push button means connected to the biasing means of said thirdswitch and extending beyond the edge of said base plate a distance suchthat completely closing said hoistway door will overcome the biasingforce of said third switch and close said second contacts and openingsaid door lwill release the biasing force and close said first contacts;

(t) lock bar means mounted on said door and having a rectangular slotformed in its upper edge such that said slot will receive and hold saidsecond pin when said door is completely closed and said cam is in itsfirst rotational position and will free said second pin just prior tothe poin-t at which said cam is in its second rotational position;

(u) a source of electrical energy;

(v) fourth switch means which is closed by the elevator car when saidcar reaches the iioor at which the interlock mechanism is located;

(w) a first electrical circuit serially connecting said source of energyto said fourth switch, `said coil of said solenoid, said second switch,and said first contacts of third switch; and

(X) a second electrical circuit serially :connecting said source ofenergy to said second contacts of said third swtich, said first switchand an interlock mechanism located on another floor.

doors, comprising:

(a) latch means having one portion thereof mounted on a door and asecond portion mounted on a wall forming the opening for said door;

(b) said first and second portions of said latch means being releasablycoupled together until said door is opened a predetermined smalldistance and decoupled when said door is opened a distance greater thansaid predetermined distance;

(c) electrically-operated limiter means operatively associated with oneof said portions of said latch means and adapted to prevent said latchmeans for coupling and said door for opening a distance greater thansaid predetermined distance when said limiter means is in a vtirstcondition of energization and to permit said latch means to decouple andsaid door to open a `distance greater than said predetermined distancewhen said limiter means is in a second condition of energization;

(d) switch means responsive to a changing condition and adapted toalternately connect said limiter means to and disconnect said limitermeans from a source of electrical energy in response to changes in saidcondition;

(e) spring means operatively connected to that portion of said latchmeans with which said limiter means is associated and adapted to applytension to said latch means and pull said door to a completely closedposition when said door is opened a distance less than saidpredetermined distance and said limiter means 3. An electro-mechanicalinterlock mechanism for doors, comprising: Y

(a) latch means having one portion thereof mounted on a door and asecond portion mounted on a wall Y forming the opening for said door;

(b) said first and second portions of said latch means being releasablycoupled together until said door is opened -a predetermined smalldistance and decoupled when said door is opened a distance greater thansaid predetremined distance;

(c) electrically-operated limiter means operatively associated with oneof said portions of said latch means and adapted to prevent said latchmeans for decoupling and said door from opening a distance greater thansaid predetermined distance when said limiter means is in a firstcondition of energization and to permit said latch means to decouple andsaid door to open a distance greater than said predetermined distancewhen said limiter means is in a second condition of energization;

(d) switch means responsive to a changing condition and adapted toalternately connect said limiter means to and disconnect said limitermeans from a source of electrical energy in response to changes in saidcondition;

(e) spring means operatively connected to thatrportion of said latchmeans with which said limiter means is associated and adapted to applytension to said latch means and pull said door to a completely closedposition when said door is opened a distance less than saidpredetermined distance and said limiter means is in a position toprevent said latch means from decoupling, and to apply tension to saidlatch means to hold said latch means in its decoupled position when saidlimiter means is in a position to permit said latch means to decouple.

4. An electro-mechanical interlock mechanism for doors, comprising:

(a) latch means having one portion thereof mounted on a door and asecond portion mounted on a wall forming the opening for said door;

(b) said first and second portions of said latch means being releasablycoupled together until said door is opened a predetermined smalldistance and decoupled when said door is opened a distance greater thansaid predetermined distance;

(c) electrically-operated limiter means operatively associated with oneof said portions of said latch means and adapted to prevent said latchmeans from decoupling and said door for opening a distance greater thansaid predetermined distance when said limiter means is in a firstcondition of energization and to permit said latch means to decouple andsaid door to open a distance greater than said predetermined distancewhen said limiter means is in a second condition of energization;

(d) first switch means responsive to a changing condition and adapted toalternately connect said limiter means to and disconnect said limitermeans from a source of electrical energy in response to changes in saidcondition;

(e) second switch means adjacent to and operated by said limiter meansand adapted to alternately connect said source of electrical energy to aremotely located mechanism when said limiter means is in a position toprevent said latch means from decoupling and disconnect said source ofelectrical energy from said remotely located mechanism when said limitermeans is in a position to permit said latch means to decouple.

5. An electro-mechanical interlock mechanism for doors, comprising:

(a) latch means having one portion thereof mounted 9 on a door and asecond portion mounted on a wall forming the opening for said door;

(b) said first and second portions of said latch means being releasablycoupled together until said door is opened a predetermined smalldistance and decoupled when said door is opened a distance greater thansaid predetermined distance;

(c) electrically-operated limiter means operatively associated with oneof said portions of said latch means and adapted to prevent said latchmeans from decoupling and said door from opening a distance greater thansaid predetermined distance when said limiter means is in a rstcondition of energization and to permit said latch means to decouple andsaid door to open a distance greater than said predetermined distancewhen said limiter means is Vin a second condition of energization;

(d) first switch means respnosive to a changing condition and adapted toalternately connect said limiter means to and disconnect said limitermeans from a source of electrical energy in response to changes in saidcondition;

(e) second switch means adjacent to and operated by said door andadapted to alternately connect said source of electrical energy to saidlimiter means when said door is open, and disconnect said source ofelectrical energy from said limiter means when said `door is closed; and

(f) third switch means adjacent to and operated by said limiter meansand adapted to alternately connect said source of electrical energy to aremotely located mechanism when said limiter means is in a position toprevent said latch means from decoupling and disconnect said source ofelectrical energy from said remotely located mechanism when said limitermeans is in a positiot1 to permit said latch means to decouple.

6. An electro-mechanical interlock mechanism tor doors, comprising:

(a) latch means having one portion thereof mounted on a door and asecond portion mounted on a wall forming the opening for said door;

(b) said rst and second portions of said latch means being releaseablycoupled together until said door is opened a predetermined smalldistance and decoupled when said door is opened a distance greater thansaid predetermined distance;

(c) electrically-operated limited means operatively associated with oneof said portions of said latch means and adapted to prevent said latchmeans from decoupling and said door from opening a distance greater thansaid predetermined distance when said limited means is in a rstcondition of energization and to permit said latch means to decouple andsaid door to open a distance greater than said predetermined distancewhen said limiter means is in a second condition of energization;

(d) rst switch means responsive to a changing condition and adapted toalternately connect said limiter means to and disconnect said limitermeans from a source of electrical energy in response to changes in saidcondition;

(e) second switch means adjacent to and operated by that portion of saidlatch means with which said limiter means is associated and adapted toalternately connect said source of electrical energy to said limitermeans when said door is closed and while said door is open less thansaid predetermined distance and disconnect said source of electricalenergy from said limiter means when said door is opened a distancegreater than said predetermined distance.

7. An electro-mechanical interlock mechanism for doors, comprising:

(a) latch means having one portion thereof mounted on a door and asecond portion mounted on a wall forming the opening for said door;

t b) said tirst and second portions of said latch means 8. Anelectro-mechanical doors, comprising:

(a) latch means having one portion thereof mounted 1 ti beingreleaseably coupled together until said door is opened a predeterminedsmall distance and decoupled when said door is opened a distance greaterthan said predetermined distance;

(c) electrically-operated limiter means operatively as- (d) first switchmeans responsive to a changing condition and adapted to alternatelyconnect said limiterV means to and disconnect said limiter means from asource of electrical energy in response to changes in said condition;

(e) second switch means adjacent to and operated by said door andadapted to alternately connect said source of electrical energy to saidlimiter means when said door is open, and disconnect said source ofelectrical energy from said limiter means when said door is closed; and

(f) third switch means adjacent to and operated by said limiter meansand adapted to alternately connect said source of electrical energy to aremotely located mechanism when said limiter means is in a position toprevent said latch means from decoupling and disconnect said source ofelectrical energy from said remotely located mechanism when said limitermeans is in a position to permit said latch means to decouple;

(g) fourth switch means adjacent to and operated by that portion of saidlatch means with said limiter means is associated and adapted toalternately connect said source of electrical energy to said limitermeans until said door is opened said predetermined distance anddisconnect said source of electrical energy from said limiter means whensaid door is opened a distance greater than said predetermined distance.

interlock mechanism for on a door and a second portion mounted on a wallforming the opening for said door;

(b) said tirst and second portions of said latch means being releaseablycoupled together until said door is opened a predetermined smalldistance and decoupled when said door is opened a distance greater thansaid pretedetermined distance;

(c) electrically-operated limiter means operatively associated with oneof said portions of said latch means and adapted to prevent said latchmeans from decoupling and said door from opening a distance greater thansaid predetermined distance when said limiter means is in a firstcondition of energization and to permit said latch means to decouple andsaid door to open a distance greater than said predetermined distanceWhen said limiter means is in a second condition of energization;

(d) rst switch means responsive to a changing condition and adapted toalternately connect said limiter means to and disconnect said limitermeans from a source of electrical energy in response to changes in saidcondition;

(e) second switch means adjacent to and operated by said door andadapted to alternately connect said source of electrical energy to saidlimiter means when said door is open, and disconnect said source ofenergy from said limiter means when said door is closed;

(f) spring means operatively connected to that portion of said latchmeans with which said limiter means is 9. An electro-mechanicalinterlock mechanism for doors, comprising:

(a) latch means having one portion thereof mounted on a door and asecond portion mounted on a wall forming the opening for said door;

(b) said iirst and second portions of said latch means being releasablycoupled together until said door is opened a predetermined smalldistance and decoupled when said door is opened a distance greater thansaid predetermined distance;

(c) electrically-operated limiter means operatively associated with onsof said portions of said latch means and adapted to prevent said latchmeans from decoupling and said door from opening a distance greater thansaid predetermined distance when said limiter means is in a firstcondition of energization and to permit said latch means to decopule andsaid door to open a distance greater than said predetermined distancewhen said limiter means is in a second condition of energization;

(d) iirst switch means responsive to a changing condition and adapted toalternately connect said limiter means to and disconnect said limitermeans from a source of electrical energy in response to changes in saidcondition;

(e) second switch means adjacent to and operated by said door andadapted to alternately connect said source of electrical energy to saidlimiter means when said door is open, and disconnect said source ofenergy from said limiter means when said door is closed;

(f) spring means operatively connected to that portion of said latchmeans with which said limiter means is associated and adapted to applytension to said latch means and pull said door to a completely closedposition when said door is opened a distance less than saidpredetermined distance and said limiter means is in a position toprevent said latch means from decoupling and to apply ltension to saidlatch means to hold said latch means in its decoupled position when saidlimiter means is in a position to permit said latch means to decouple.

10. An eletctro-mechanical interlock mechanism for doors, comprising:

(a) latch means having one portion there-of mounted on a door and asecond portion mounted on a wall forming the opening for said door;

(b) said latch means; including a rotatable cam, forming one of saidportions, releasably coupled to a lock bar element, forming the other ofsaid portions, until said door is opened a predetermined vsmall distanceand decoupled when said door is opened a distance greater than saidpredetermined distance;

(c) electrically-operated limiter means operatively associated with saidcam of said latch means and ladapted to prevent said latch means fromdecoupling and said door from opening a distance greater than saidpredetermined distance when said limiter means is in a rst condition ofenergization and to permit said latch means to decouple and said door toopen a distance greater than said predetermined distance 'when saidlimiter means is in a second condition of energization;

(d) rst switch means responsive to a changing condition and adapted toalternately connect said limiter means to and disconnect said limitermeans from a source of electrical energy in response to changes in saidcondition;

`(e) second switch 11.16.21.115 .adjacent to and operated by said doorand adapted to alternatelyl connect said source of electrical energy tosaid limiter means when said door is open, and disconnect said s-ourceof electrical energy from said limiter means when said door is closed;and

(f) third switch means adjacent to and operated by limiter means andadapted to alternately connect said source of electrical energy to aremotely located mechanism when said limiter means is in a position toprevent said latch means from decoupling and disconnect said source ofelectrical energy from said remotely located mechanism when said limitermeans is in a position to permit said latch means to decouple;

(g) fourth switch means adjacent to and operated by that portion of saidlatch means with which said limiter means is associated and adapted toalternately connect said source of electrical energy to said limitermeans until said door is opened said predetermined distance anddisconnect said source of electrical energy from said limiter means whensaid door is opened a distance greater than said predetermined distance.

11. An electro-mechanical interlock mechanism for doors, comprising:

(a) latch means having one portion thereof mounted on a door and asecond portion mounted on a Wall forming the opening for said door;

(b) said rst and second portions of said latch means being releasablycoupled together until said door is opened a predetermined smalldistance and decoupled when said door is opened a distance greater thansaid predetermined distance;

(c) a movable core electromagnet operatively associated with one of saidportions of said latch means and adapted to 'prevent said latch meansfrom decoupling, and said door from opening a distance greater than saidpredetermined distance when said movable core electromagnet is in afirst condition of energization, and to permit said latch means todecouple and said door to open a distance greater than saidpredetermined distance when said movable core electromagnet is in asecond c-ondition of energization;

(d) first switch means responsive to a changing condition and adapted toalternately connect said electromagnet to and disconnect saidelectromagnet yfrom a source of electrical energy in response to changesin said condition;

(e) second switch means adjacent to and operated by said door andadapted to alternately connect said source of electrical energy to saidelectromagnet when said door is open, and disconnect said source ofelectrical energy from said electromagnet when said door is closed; and

(f) third switch means adjacent to and operated by said electromagnetand adapted to alternately connect said source of electrical energy to aremotely located mechanism when said electromagnet is in a position toprevent said latch means from decoupling and disconnect said source ofelectrical energy from said remotely located mechanism when saidelectromagnet is in a position t-o permit said latch means to decouple;

(g) fourth switch means adjacent to and operated by that portion of saidlatch means with which said electromagnet is associated and adapted toalternately connect said source of electrical energy to saidelectromagnet until said door is opened said predetermined distance anddisconnect said source of electrical energy from said electromagnet whensaid door is opened a distance greater than said predetermined distance.

12. An electro-mechanical interlock mechanism for doors, comprising:

(a) latch means having one portion thereof mounted on a door and asecond portion mounted on a Wall forming the opening for said d-oor;

(b) said -latch means; including, a rotatable cam, forming one of saidportions, releasably coupled to a lock bar element, forming the other ofsaid portions, until said door is opened a predetermined small distanceand decoupled when said door is opened a distance ygreater than saidpredetermined distance;

(c) a movable core electromagnet operatively associated with one of saidportions of said latch means and adapted to prevent said latch meansfrom decoupling, and said door from opening a distance greater than saidpredetermined distance when said movable core electromagnet is in afirst condition of energization, and to permit said latch means Atodecouple and said door to open a distance greater than saidpredetermined distance when said movable core electromagnet is in asecond condition of energization;

(d) rst switch means responsive to a changing condition and adapted toalternately connect said electromagnet to and disconnect saidelectromagnet from a source of electrical energy in response to changesin said condition;

(e) second switch means adjacent to and operated by said door andadapted to alternately connect said source of electrical energy to saidelectroma-gnet when said door is open, and disconnect said source ofelectrical energy from said electromagent when said door is closed; and

(f) third switch means adjacent to and operated by said electromagnetand adapted to alternately connect said source -of electrical energy toa remotely located mechanism when said electromagnet is in a position toprevent said latch means from decoupling and disconnect said source ofelectrical energy from said remotely located mechanism when saidelectromagnet is in a position to permit said latch means to decouple;

(g) fourth switch means adjacent to and operated by said cam and adaptedto alternately connect said source of electrical energy to saidelectromagnet until ysaid door is opened said predetermined distance anddisconnect said source of electrical energy from said electromagnet whensaid door is opened a distance greater than said predetermined distance.

References Cited by the Examiner UNITED STATES PATENTS 836,572 ll/l906Gill et al 187-31 963,567 7/1910 Humphrey 187-31 1,090,170 3/1914Schenek 187-31 1,479,027 l/ 1924 Claney 187-31 SAMUEL F. COLEMAN,Primary Examiner.

1. AN ELECTRO-MECHANICAL INTERLOCK MECHANISM FOR ELEVATOR HOISTWAY DOORSCOMPRISING: (A) A GENERALLY RECTANGULAR BASE PLATE ATTACHED TO THE DOORJAMB OF THE HOISTWAY OPENING IN A VERTICAL MANNER; (B) A GENERALLYDISC-SHAPED CAM MEMBER ROTATABLY MOUNTED ON SAID BASE PLATE NEAR THECENTER THEREOF; (C) SUPPORT BLOCK MEANS RIGIDLY ATTACHED TO SAID BASEPLATE ABOVE SAID CAM AND IN THE IMMEDIATE VICINITY THEREOF; (D) TWOSTOPS RADIALLY PROTRUCDING FROM SAID EDGE OF SAID CAM AND ADAPTED TOCOOPERATIVELY ENGAGE SAID BLOCK, A FIRST OF SAID STOPS ENGAGING SAIDBLOCK AT A FIRST ROTATIONAL POSITION OF SAID CAM AND THE SECOND OF SAIDSTOPS ENGAGING SAID BLOCK AT A SECOND ROTATIONAL POSITION OF SAID CAMABOUT 80* OF ROTATION FROM SAID FIRST POSITION; (E) A FIRST CYLINDRICALPIN MEANS MOUNTED ON SAID CAM AND HAVING ITS AXIS PERPENDICULAR TO THEFACE OF SAID CAM AND ITS CIRCUMFERENTIAL EDGE COINCIDING WITH THECIRCUMFERENTIAL EDGE OF SAID CAM AND POSITIONED ON SAID CAM SUCH THAT ITWILL BE ON ONE SIDE OF A VERTICAL PLANE PASSING THROUGH THE AXIS OFROTATION OF SAID CAM WHEN SAID CAM IS IN ITS SAID FIRST ROTATION OF SAIDSITION AND ON THE OTHER SIDE OF SAID PLANE WHEN SAID CAM IS IN ITSSECOND ROTATIONAL POSITION; (F) SECOND CYLINDRICAL PIN MEANS MOUNUTED ONSAID CAM AND HAVING ITS AXIS PERPENDICULAR TO THE FACE OF SAID CAM ANDITS CIRCUMFERENTIAL EDGE COINCIDING WITH THE CIRCUMFERENTIAL EDGE OFSAID CAM AND POSITIONED ON SAID CAM SUCH THAT ITS AXIS COINCIDES WITHSAID VERTICAL PLANE WHEN SAID CAM IS IN ITS ROTATIONAL POSITION AND MORETHAN ABOUT 30* OF ROTATION FROM SAID VERTICAL PLANE AND ON THE SAME SIDEOF SAID VERTICAL PLANE AS SAID FIRST PIN, WHEN SAID CAM IS IN ITS SECONDPOSITION OF ROTATION; (G) HELICAL SPRING MEANS HAVING ONE END ATTACHEDTO SAID FIRST PIN AND ITS OTHER END CONNECTED TO SAID BLOCK ON THE SIDEOF SAID VERTICAL PLANE TO WHICH SAID FIRST PIN ROTATES WHEN SAID CAM ISIN ITS SECOND ROTATIONAL POSITION; (H) SAID CAM HAVING A SECTORS-SHAPEDSLOT FORMED IN ITS EDGE BEGINNING AT A POINT ADJACENT SAID FIRST STOPAND EXTENDING SLIGHTLY MORE THAN ABOUT 30* OF ROTATION TOWARD SAIDSECOND STOP; (I) THIRD PIN MEANS HAVING ITS CENTRAL AXIS IN ALIGNMENTWITH SAID VERTICAL PLANE AND SLIDABLE PASSING THROUGH SAID BLOCK FORLIMITED VERTICAL MOVEMENT INTO CONTACT WITH THE UPPER EDGE OF SAID CAMIN A MANNER SUCH THAT SAID THIRD PIN WILL LIMIT THE ROTATION OF SAID CAMTO ABOUT 30* OF ROTATION, WHEN IT IS IN ITS DOWNWARD POSITION AND INSAID SECTOR-SHAPED SLOT, AND WILL CONTACT THE OUTERMOST PERIPHERAL EDGEOF SAID CAM WHEN IT IS IN ITS UPPERMOST POSITION AND SAID CAM ISAPPROACHING SAID SECOND ROTATIONAL POSITION; (J) A SOLENOID MOUNTED ONSAID BASE PLATE ADJACENT ITS UPPER END AND HAVING A MOVABLE CYLINDRICALBORE WHOSE CENTRAL AXIS IS IN ALIGNMENT WITH THE AXIS OF SAID THIRD PIN;(K) MANUALLY OPERABLE LIFT MEANS HOLDING SAID CORE AND SAID THIRD PINRIGIDLY TOGETHER AND ADAPTED TO MOVE SAID THIRD PIN BETWEEN ITSLOWERMOST AND ITS UPPERMOST POSITION; (L) FIRST SWITCH MEANS, NORMALLYBIASED IN ITS OPEN POSITION, MOUNTED ON SAID SUPPORT BLOCK; (M) COLLARMEANS RIGIDLY MOUNTED ABOUT SAID THIRD PIN MEANS ABOVE SAID SUPPORTBLOCK; (N) ARM MEANS PIVOTALLY MOUNTED ON SAID FIRST SWITCH AND HAVINGITS FREE END IN CONTACT WITH THE LOWERMOST EDGE OF SAID COLLAR, SAID ARMBEING HELD OUTWARDLY BY THE BIASING FORCE OF SAID SWITCH WHEN SAID THIRDPIN IS IN ITS MOST UPPERMOST POSITION AND BEING FORCED INWARDLY TOOVERCOME THE BIASING FORCE OF SAID SWITCH AND CLOSE SAID SWITCH WHENSAID THIRD PIN IS IN ITS LOWERMOST POSITION; (O) SAID CAM ALSO HAVING AFLAT CHORD FORMED ON ITS EDGE BETWEEN SAID FIRST STOP AND SAID FIRSTPIN; (P) SECOND SWITCH MEANS, NORMALLY BIASED IN ITS OPEN POSITION,MOUNTED BELOW SAID CAM; (Q) FOLLOWER MEANS PIVOTALLY MOUNTED ON SAIDSECOND SWITCH AND HAVING ITS FREE END IN CONTACT WITH THE EDGE OF SAIDCAM, SAID FOLLOWER BEING HELD OUTWARDLY BY THE BIASING FORCE OF SAIDSWITCH WHEN SAID CAM IS IN ITS SECOND POSITION OF ROTATION AND SAIDFOLLOWER IS IN CONTACT WITH THE STRAIGHT CHORD SECTION OF SAID CAM ANDBEING FORCED INWARDLY TO OVERCOME THE BIASING FORCE OF SAID SWITCH ANDCLOSE SAID SWITCH WHEN SAID CAM IS IN ITS SECOND ROTATIONAL POSITION ANDSAID FOLLOWER IS IN CONTACT WITH THE CIRCULAR SECTION OF SAID CAM; (R)THIRD SWITCH MEANS MOUNTED ON SAID BASE PLATE BELOW SAID CAM ANDNORMALLY BIASED TOWARD A FIRST SETOF CONTACTS TO CLOSE SAID FIRSTCONTACTS AND NORMALLY BIASED AWAY FROM A SECOND SET OF CONTACTS TO HOLDSAID SECOND CONTACTS OPEN UNTIL SAID BIASING FORCE IS OVERCOME; (S) PUSHBUTTON MEANS CONNECTED TO THE BIASING MEANS OF SAID THIRD SWITCH ANDEXTENDING BEYOND THE EDGE OF SAID BASE PLATE A DISTANCE SUCH THATCOMPLETELY CLOSING SAID HOISTWAY DOOR WILL OVERCOME THE BIASING FORCE OFSAID THIRD SWITCH AND CLOSE SAID SECOND CONTACTS AND OPENING SAID DOORWILL RELEASE THE BIASING FORCE AND CLOSE SAID FIRST CONTACTS; (T) LOCKBAR MEANS MOUNTED ON SAID DOOR AND HAVING A RECTANGULAR SLOT FORMED INITS UPPER EDGE SUCH THAT SAID SLOT WILL RECEIVE AND HOLD SAID SECOND PINWHEN SAID DOOR IS COMPLETELY CLOSED AND SAID CAM IS IN ITS FIRSTROTATIONAL POSITION AND WILL FREE SAID SECOND PIN JUST PRIOR TO THEPOINT AT WHICH SAID CAM IS IN ITS SECOND ROTATIONAL POSITION; (U) ASOURCE OF ELECTRICAL ENERGY; (V) FOURTH SWITCH MEANS WHICH IS CLOSED BYTHE ELEVATOR CAR WHEN SAID CAR REACHES THE DOOR AT WHICH THE INTERLOCKMECHANISM IS LOCATED; (W) A FIRST ELECTRICAL CIRCUIT SERIALLY CONNECTINGSAID SOURCE OF ENERGY TO SAID FOURTH SWITCH, SAID COIL OF SAID SOLENOID,SAID SECOND SWITCH, AND SAID FIRST CONTACTS OF THIRD SWITCH; AND (X) ASECOND ELECTRICAL CIRCUIT SERIALLY CONNECTING SAID SOURCE OF ENERGY TOSAID SECOND CONTACTS OF SAID THIRD SWITCH, SAID FIRST SWITCH AND ANINTERLOCK MECHANISM LOCATED ON ANOTHER FLOOR.